Based on substantial evidence that an infectious agent or agents may play a role in the etiology of at least a subtype of schizophrenic illnesses, we are searching for evidence of an infectious or toxic substance in schizophrenic brains. Studies undertaken to date include immunocytochemical investigations for antigens to cytomeglavirus (CMV), Herpes simplex virus (HSV), varicella virus (VAV), rubella and mumps. Although sporadic cases have shown positive results with immunocytochemical studies, these have been inconsistent and rare. We have also undertaken in situ hybridization probes for CNV, and cultivation of schizophrenic and control brain specimens on cultures of human and non-human neural tissue. Using special stains for glia we have evaluated the brains of guinea pigs and primates previously innoculated with schizophrenic and control brain tissue.